Display links at the top of an obsidian page for the previous and next files

display-previous-and-next-links.js

```dataviewjs

let currentFilePath = dv.current().file.path;
let currentFileDir = dv.current().file.folder;

let currentSubPagesSorted = dv.pages('"' + currentFileDir + '"').sort(b => b.file.name, 'asc').values;

function getIndex(options) {
	let direction = options.direction;
	let targetIndex = 0;

	for (let i = 0; i < currentSubPagesSorted.length; i++) {
		let filePath = currentSubPagesSorted[i].file.path;
		if (filePath == currentFilePath) {
			if (direction == 'forward') {
				targetIndex = i + 1;
				break;
			} 

			if (direction == 'backwards') {
				targetIndex = i - 1;
				break;
			}
		}
	}
	return targetIndex
}

function getPrevFileLink(options) {
	let prevIndex = options.prevIndex;
	if (prevIndex == -1) {
		prevIndex = currentSubPagesSorted.length - 1;
	}
	let prevPage = currentSubPagesSorted[prevIndex];
	let prevPageFileLink = dv.fileLink(prevPage.file.link.path, false, "<< " + prevPage.file.name);
	return prevPageFileLink
}

function getNextFileLink(options) {

	let nextIndex = options.nextIndex

	if (nextIndex == currentSubPagesSorted.length) {
		nextIndex = 0;
	}

	let nextPage = currentSubPagesSorted[nextIndex];
	let nextPageFileLink = dv.fileLink(nextPage.file.link.path, false, nextPage.file.name + " >>");
	return nextPageFileLink;
}

// prevIndex
let prevIndex = getIndex({'direction': 'backwards'});
let prevFileLink = getPrevFileLink({'prevIndex': prevIndex});

// nextIndex
let nextIndex = getIndex({'direction': 'forward'});
let nextFileLink = getNextFileLink({'nextIndex': nextIndex});
dv.span(prevFileLink + ' | ' + nextFileLink);
```